As the debris discovered on the shores of Reunion Island Wednesday seems increasingly likely to be from the wreck of Malaysia Airlines Flight MH370, the final resting place of the Boeing 777 aircraft that disappeared in March 2014 while flying over Vietnam will be confirmed. But what caused the plane's disappearance and how it crashed will remain a mystery until engineers and aviation security specialists have the opportunity to thoroughly examine more pieces.

MH370 departed from Kuala Lampur heading to Beijing on March 8. About an hour into flight, the transponder and secondary radar tracking turned off, ending communication with the ground. About two days later, Malaysian military radar tracked the plane going southwest after taking a sharp left turn, fuelling speculation about a rogue pilot or a terrorist hijacking. 

While the flaperon discovered Wednesday may not solve the mystery of Malaysia flight 370, the potential breakthrough discovery does have the opportunity to rule out some of the more radical conspiracy theories on what happened to MH370 and the 239 people it carried. Here are some of the most-cited scenarios for why the Malaysia Airlines Flight could have disappeared.

MH370 debris French gendarmes and police carry a large piece of plane debris which was found on the beach in Saint-Andre, on the French Indian Ocean island of La Reunion, July 29, 2015. France's BEA air crash investigation agency said it was examining the debris, in coordination with Malaysian and Australian authorities, to determine whether it came from Malaysia Airlines Flight MH370, which vanished last year in one of the biggest mysteries in aviation history. Picture taken July 29, 2015. Photo: Reuters/Zinfos974/Prisca Bigot

Mechanical Failure

One of the most likely scenarios involves some sort of mechanical failure in the engines or controls making it impossible for the plane to be operated. Some have even speculated that the previous lack of debris was because plane parts broke apart mid-flight, making any wreckage unrecognizable.

"The fact that we are unable to find any debris so far appears to indicate that the aircraft is likely to have disintegrated at around 35,000 feet," a source involved in the investigations in Malaysia said at the time, reported the Sydney Morning Herald.


MH370 Shot Down By U.S. Military Base

Marc Dugain, the former head of a French regional airline, proposed that the plane was shot down by the United States while it was flying toward its military base on the British island of Diego Garcia in the Indian Ocean. A similar theory by the book "Flight MH370: The Mystery," by Nigel Cawthorne suggested that the plane was shot down accidentally in the South China Sea during a joint US-Thai military exercise.

Despite its implausability, the theory grew so popular in China that United States officials were forced to deny it, according to The Telegraph.

"There was no indication that MH70 flew anywhere near the Maldives or Diego Garcia," an offical from the US embassy in Malaysia told the Malaysian newspaper, The Star

Flight MH370 Fast Response Vehicle Crew members ride a fast response craft from the Australian Defense Vessel Ocean Shield as they continue to search for debris in the southern Indian Ocean for the missing Malaysian Airlines flight MH370 in this picture released by the Australian Defense Force April 8, 2014. Photo: Australian Defense Force/Handout via Reuters

Pilot Suicide

Like Germanwings Flight 9525, which crashed in the French Alps in March 2015, MH370's disappearance could have come from a rogue pilot committing suicide. While no evidence has emerged suggesting that the captain of the flight, Zaharie Ahmad Shah, or co-pilot Fariq Abdul Hamid planned the crash, the plane's sudden left turn outside of the directed flight path may demonstrate some form of foul play.

MH370 families BEIJING, CHINA - MARCH 08: Catherine Gang, whose husband is a missing passenger on Malaysia Airlines flight MH370 holds a sign as she and other relatives protest after trying to hold a prayer at the Lama Temple on March 8, 2015 in Beijing, China. There were 239 people on board the flight when it disappeared March 8, 2014 en route from Kuala Lumpur to Beijing. A piece of metal debris discovered on the Indian ocean island of Reunion could possibly be to be from the aircraft. Photo: Getty Images

Electrical Fire After Takeoff

The simplest scenario is also the most-likely. Chris Goodfellow, a Canadian Class-1 instrumented-rated pilot, told Wired that MH370 encountered a slow-burning electrical fire an hour into take off. Upon discovery, Goodfellow said, the crew would have shut off all circuits on the plane, including those communicating with the ground, in an effort to isolate and contain the fire from continuing to spread.

The pilots, in this scenario, turned left during the flight after discovering the fire, hoping to reach the Palau Langkawi airstrip that was  both in that direction and the easiest site to land nearby. By the time the plane would have been ready to land, the fire would have already destroyed the aircraft's controlling mechanisms.

Goodfellow also suggested that the same procedure could have occurred if one of the front landing gear tires was underinflated and caught on fire during an overheated takeoff, producing incapacitating smoke and rendering the controls inoperable.